The present invention is generally related to retractable tape rule assemblies and more particularly to tape rule assemblies of the spring retractable type.
Spring retractable rule assemblies have been available commercially for many years. It is also known in the tape rule industry to provide a concavo-convex tape rule blade with a standard width dimension of xc2xcxe2x80x3, xc2xdxe2x80x3, xc2xexe2x80x3 or 1xe2x80x3, with a height dimension as high as 0.226xe2x80x3 as disclosed in U.S. Pat. No. 4,429,462 to Rutty et al. There always exists a need to provide a retractable rule assembly that presents new and innovative blade configurations.
The present invention comprises a retractable rule assembly that includes a housing assembly and a reel rotatably mounted in the housing assembly. An elongated blade formed of a ribbon of metal is mounted on the reel. One end of the blade is connected to the reel. The blade is constructed and arranged with respect to the housing assembly to extend from a position tangential to the reel outwardly through a spaced opening in the housing assembly. A coil spring that is formed of a ribbon of metal has a construction and arrangement between the housing assembly and the reel to rotate the reel in the housing assembly in a direction to wind the elongated blade about the reel when the blade is extending outwardly of the housing assembly opening. The blade has a xe2x80x9cnormalxe2x80x9d concavo-convex cross-sectional configuration when extended and has a flat cross-sectional configuration when it is wound about the reel so that the wound reel is disposed about the reel in an abutting volute coil formation. A blade holding assembly is provided which can hold the blade in any position of extension outwardly of the housing assembly opening and to release the blade from any position in which it is held. The blade has a width in its flattened configuration thereof within the range of 1.10xe2x80x3-1.5xe2x80x3 and a height in its concavo-convex configuration thereof within the range of 0.25xe2x80x3-0.40xe2x80x3.
It is also contemplated to provide a wide range of tape assembly embodiments having increased blade standout. More particularly, in the more specific aspects of the present invention, it is a further objective to provide a retractable rule assembly having a blade constructed according to the principles briefly described above to provide the improved standout characteristics previously described with any combination of the following additional features:
1. A retractable rule assembly wherein a relatively short free end portion of the blade has a clear film of plastic material adhered to a concave side thereof.
2. A retractable rule assembly wherein the metal ribbon of the spring has a width which is 95%-120% of the width of the metal ribbon of the blade.
3. A retractable rule assembly wherein the blade has an end hook member on the free end thereof, the end hook member being formed of sheet metal of a predetermined thickness to include a concavo-convex mounting portion having a U-shaped hook portion bent at a generally right angle from an end thereof, the end hook member being mounted on the free end of the blade with the mounting portion thereof secured in limited sliding engagement with a concave side of the free end of the blade so that the rule can be measured externally from an exterior surface of the U-shaped hook portion or internally from an interior surface of the U-shaped hook portion, the U-shaped hook portion including a bight section extending transversely from a convex side of the free end of the blade and spaced leg sections extending beyond transversely spaced corners of the free end of the blade.
4. A retractable rule assembly wherein the housing assembly includes a pair of cooperating housing members, each including an end wall having a peripheral wall extending from a periphery thereof and terminating in a free edge, the housing members being fixed together with their free edges interengaged by a plurality of bolts extending through one of the housing members and threadedly engaged in the other at spaced positions adjacent the peripheral walls thereof and by a fixed reel spindle having a non-circular interengaging recess-projection connection at each end thereof with the central interior of the adjacent end wall, each end of the spindle being interiorly threaded to threadedly receive a bolt therein extending through a central hole in the adjacent end wall and the recess-projection connection between the central hole and threaded interior.
5. A retractable rule assembly wherein the housing assembly includes a fitment defining a part of the housing assembly opening adjacent a convex side of the blade, the fitment having a plurality of tangentially extending transversely spaced elongated ridges defining surfaces for engaging the convex side of the blade extending tangentially from the reel to said housing assembly opening.
6. The housing assembly includes a bottom wall having an exterior portion at an end position adjacent the housing assembly opening which projects below the exterior surface portion extending therefrom toward an opposite end to provide a finger grip enhancing configuration.
7. The housing opening has a height dimension which exceeds the height dimension of the blade an amount that is at least approximately equal to the amount the hook portion extends below the bottom end surface of the housing assembly at the housing opening.
In the broader aspects of the present invention, it is an objective to provide any known retractable rule assembly with improved blade standout by constructing a blade therefor to have the blade cross-sectional geometry briefly described above and/or the blade dimensions as previously described.
These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims.